ParaSpace — [H-09] UniswapV3 tokens of certain pairs will be wrongly valued

Source & credit. Reproduction of a public audit finding curated by AuditVault — the original finding: 15982-h-09-uniswapv3-tokens-of-certain-pairs-will-be-wrongly-value. Standalone Foundry PoC and full write-up: 15982-h-09-uniswapv3-tokens-of-certain-pairs-will-be-wrongly-value_exp in the evm-hack-registry mirror.

Vulnerability classes: arithmetic/decimal-mismatch · false liquidation

Reproduction: self-contained Foundry PoC with only forge-std — no fork. Full trace: output.txt.

AuditVault taxonomy: lang/solidity · platform/code4rena · severity/high · sector/dex · sector/lending · sector/oracle · genome: decimal-mismatch · variant · token-decimal-normalization

Key info#


Impact	HIGH — extreme price ratios zero `sqrtPriceX96`; healthy UniV3 LP falsely liquidatable
Protocol	ParaSpace
Vulnerable code	`UniswapV3OracleWrapper._getOracleData` same-decimal `sqrtPriceX96` branch
Bug class	Integer division truncates before fixed-point scale
Finding	Code4rena 2022-11-paraspace · #15982 (H-09) · reporter Trust
Compiler	`^0.8.24` (PoC)

TL;DR#

Same-decimal branch: sqrt(token0Price * 1e18 / token1Price) * 2^96 / 1e9.
If token1Price > token0Price * 1e18, inner div is 0 → sqrtPriceX96 = 0.
Amount math treats position as pure amount0 → severe undervaluation → false liquidation.

The vulnerable code#

SOLIDITY

oracleData.sqrtPriceX96 = uint160(
    (SqrtLib.sqrt(
        ((oracleData.token0Price * (10 ** 18)) / (oracleData.token1Price)) // @> VULN
    ) * 2 ** 96) / 1e9
);
// FIX: scale (e.g. multiply by 2**96) before the truncating division

Diagrams#

flowchart TD A["token1Price greater than token0Price times 1e18"] --> B["Inner ratio truncates to 0"] B --> C["sqrtPriceX96 is 0"] C --> D["getAmountsForLiquidity all amount0"] D --> E["Healthy LP under-valued"] E --> F["False liquidation"]

Impact#

Users holding UniV3 NFTs on extreme-ratio pairs can be liquidated while economically healthy.

Remediation#

Multiply by 2**96 (or use higher intermediate precision) before the division that can zero.

Sources#

AuditVault #15982
Code4rena 2022-11-paraspace
code-423n4/2022-11-paraspace@c6820a2 paraspace-core/contracts/misc/UniswapV3OracleWrapper.sol

Sources & further analysis#

Reproductions & code

Standalone PoC + full trace: 15982-h-09-uniswapv3-tokens-of-certain-pairs-will-be-wrongly-value_exp (evm-hack-registry mirror).
AuditVault finding: 15982-h-09-uniswapv3-tokens-of-certain-pairs-will-be-wrongly-value.

Alerts & third-party analyses

Web3Sec X hacked database: search.
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Solodit incident search: search.

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